A number of applications are best served by flexible hoses. Most notably, hoses connecting fixed plumbing outlets to vibrating machinery or appliances require the use of flexible hoses to prevent cracking and resultant leaks. Resilient materials, including various types of rubber and plastic, have been employed in situations requiring flexible hoses, however, a number of problems are typically encountered. The flexible materials employed in such hoses tend not to be as strong and resistant to higher pressures as solid, non-flexible materials. Further, such materials tend to stretch and further weaken under pressure, putting strain upon the points of attachment of these hoses to fittings and couplings. A number of methods have been developed to give flexible hoses the strength and durability needed while maintaining the required flexibility.
A further problem associated with hoses connecting vibrating or moving equipment, such as washing machines and dishwashers is that the hoses may develop cracks, defects and other problems that result in potentially damaging leakage. Often these leaks are small at first and are difficult to detect. If such leaks go undetected, they may become catastrophic, causing major damage to walls, floors, etc. The present invention addresses this problem by providing a visual indicator of any leak in the hose. A simple inspection of the color of the hose, visible through the transparent covering, will allow a defective hose to be timely replaced.
U.S. Pat. No. 4,699,178 issued to Washkewicz discloses a high burst strength flexible composite hose having low volumetric expansion under pressure which includes a thermoplastic core tube, one or more braided reinforcing layers of high strength aramid yarn having a tensile modulus of elasticity of about 17,000,000 psi and a tenacity of more than 20 grams per denier at room temperature, and an outer cover of elastomeric material.
U.S. Pat. No. 4,111,237 issued to Muntzner et al. describes a hydraulic brake hose comprising a polychloroprene inner tube, a reinforcing braid of twisted glass fiber yarn around the tube, a styrene-butadiene copolymer rubber cushion layer over the glass braid, a second reinforcing braid of nylon fiber yarn over the cushion layer and a cover layer of polychloroprene rubber.
U.S. Pat. No. 5,803,129 issued to Coronado et al. discloses an improved reinforced hose for conducting fluids and gases, and a method of manufacturing that hose. The improved reinforced hose includes an interior tube having an inner bore and an outer surface. The improved reinforced hose also includes an outer covering disposed directly about the outer surface of the interior tube. Such outer covering includes one or more layers of plastic threads, which are formed by disposing a plastic substance about core material.
U.S. Pat. No. 5,381,834 issued to King describes a hose assembly of the type for carrying high-pressure fluids therethrough. The hose assembly includes a tubular member and a pair of coupling members. The tubular member includes an inner liner of a fluorocarbon polymer. Yarns fabricated from fibers, including glass fibers and Aramid fibers, are braided together about the exterior of the inner liner to form a braided layer. The assembly further includes an outer fluorocarbon coating dispersed throughout the braided layer to prevent kinking or permanent deformation in the inner liner, in addition to preventing the crushing of the yarns when the ends are crimped to receive the coupling members. A conductive strip is formed on the inner liner for dissipating electrical charges that may accumulate in the inner liner.
U.S. Pat. No. 5,142,782 issued to Martucci describes a method of making a lightweight hose assembly including a step of extruding the inner liner. A nonmetallic material is then braided about the exterior of the liner. The inner liner and braided layer are then passed through a reservoir containing a solution of the fluorocarbon polymer. The solvent is then removed, leaving a fluorocarbon polymer coating dispersed throughout the braided layer.
U.S. Pat. No. 4,915,762 issued to Berlincourt et al. discloses a hose comprising an inner plastic tube covered by at least one braiding of filaments disposed in helically crossed layers around the inner tube, characterized in that the filaments are made of plastics and are so deformed in their right cross-section that the gap between any two adjacent layers which extend in the same direction as one another is at least 100% filled. The invention also relates to a process for the production of the hose.
U.S. Pat. No. 4,952,262 issued to Washkewicz, et al. discloses a method of hose construction and product formed thereby consisting of an extruded thermoplastic core tube having ferrometallic wire reinforcement windings thereon which are closely wound and providing minute spaces between the wires. The reinforced core tube structure is elevated in temperature by an induction heater which concentrates heating in the wire reinforcement and transfers heat from the wire by conduction to the outer periphery of the core tube. Supplemental conventional heaters may be used in conjunction therewith to achieve substantial temperature elevation of the wire reinforcement. Thereafter a thermoplastic cover is pressure extruded over the heated wire reinforcement and forced through the minute spaces in the reinforcement into engagement with the core tube periphery. Cool-down establishes a bond between cover, wires and core tube and a mechanically locked, integral composite hose structure.
U.S. Pat. No. 4,275,768 to Riggs, et al. discloses a longitudinally extending, circumferentially limited member is disposed upon the exterior surface of a tubular object such as hose, which member has a surface appearance contrasting to that of the exterior surface of the tubular object. Indicia are engraved within the surface of the longitudinally extending, circumferentially limited member and is rendered prominently visible by the difference in contrast between the two surface appearances.
U.S. Pat. No. 4,585,035 to Piccoli discloses a flexible hose having a braided spiral reinforcement layer having one wire braid member which remains uncrimped during braiding and a second braid member which is composed of a relatively flexible, high tenacity material which is crimped or deformed around the wire braid member at each contact point in the braided-spiral layer. The hose may be made using a flexible mandrel technique to produce a light weight hose having improved flexibility for use in high pressure applications such as in hydraulic system components.
The problems with the prior art described above include:
1. It is difficult to obtain good adhesion between the braid and the outer covering because the braid is hard to clean.
2. The outer plastic layer is uneven because it is applied over an uneven braid.
3. The outer plastic layer is typically very thin, of the order of 0.3 to 0.5 mm.
4. The outer plastic layer tends to break when the tubes are bent.
5. Stresses on the hose due to vibrating machinery may result in leaks that, if undetected, may result in major damage to surroundings.
It is an objective of the present invention to provide a flexible hose capable of withstanding vibration and jarring. It is a further objective to provide a hose capable of handling relatively high pressure without expanding in diameter. It is a still further objective of the invention to provide a hose that will not rust, corrode or oxidize. It is yet a further objective to provide a hose that will indicate a leaking condition before such leaks become catastrophic. It is a final objective to provide a hose that may be easily and inexpensively manufactured in any desired length.
While some of the objectives of the present invention are disclosed in the prior art, none of the inventions found include all of the objectives identified above.